1. Field of Technology
The present invention relates to a switchgear in an electric power reception and distribution facility, and more particularly to a switchgear that is structured with circuit breakers, current transformers, zero-phase sequence current transformers, instrument voltage transformers, and the like.
2. Background of Art
In general, a switchgear for electric power reception and distribution is structured by placing, in its case, circuit breakers, disconnecting switches, current transformers, zero-phase sequence current transformers, instrument voltage transformers, and the like. The circuit breaker and disconnecting switch are mounted as a unit on a cart that can be drawn. The circuit breaker and disconnecting switch are structured so that they can move away from and toward conductors at a power supply side and conductors at a load side when the cart moves.
In this type of electric power reception and distribution switchgear, to improve the reliability in protection against earth fault for the entire load including the circuit breaker, save in maintenance labor, and prolong the service life, the zero-phase sequence current transformer is disposed near the power supply of the circuit breaker included in the unit, and solid-insulated main buses are accommodated in a main bus room disposed separately from the unit rooms in which the units are accommodated (see Patent Document 1, for example).
Patent Document 1: Japanese Patent Laid-open No. 2008-43181